Furnace wall



Apri 29, 1941. M. H. Kub-.NER Erm,

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I 'rwa/wo MAX H. KUHNER GUSTAV A. REHM wwfi patented VApr. 29, i941 2,239,896 FURNACE WALL Max H. Kulmer and Gustav A. Rehm, Worcester, Mass., assis-nora to Riley Stoker Corporation,

Worcester, setta Mass., a corporation of Massachu- Application July 4, 1939, Serial No. 282,773

(Cl. 12M) Claims.

-This invention relates to furnace walls, and more particularly to walls of the type having a row of parallel metal tubes through which a suitabte fluid is circulated to cool the wall.

Walls of this type are commonly used in steam boiler furnaces, the wall tubes being connected 4 to the boiler so that water may be circulated through the tubes. Such a water cooled wall will absorb radiant neat very rapidly from the burning fuel, and large quantities of steam will be generated in the tubes. Under some circumstances it is desirable to limit the absorption of radiant heat so that the furnace temperature will remain high enough to ensure proper ignitionand combustion of the fuel. For this purpose it khas been proposed to cover the inner or heat exposed side of the water wall tubes with refractory material, but great difficulty has been experienced -in securing such material in place against the tubes. This is particularly true in the case of water wall tubes which are rather closely spaced, since the refractory material cannot be satisfactorily interlocked with the tubes in auch a construction.

It is accordingly one object of the invention to provide a comparatively simple and reliable constmction for a fluid cooled furnace wall having a sexieslof parallel metal tubes andV means forming a shield to limit the absorption of radiant Iheat by the tubes.

It is a further object of the invention to provide a fluid cooled furnace wall having relatively closely spaced metal tubes and refractory material secured to the heat exposed side of the tubes in a simple and dependable manner.

It is a further object of the invention to provide a new and advantageous anchoring device particularly suitable for securing refractory material to the metal tubes of a fluid cooled furnace wail.

With these and other ob'lects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specificationy and covered by the claims appended hereto.

Referring to the drawing illustrating one embodiment of the invention, and in which like reference numerals indicate like parts,

Fig. 1 is an elevation of a fluid cooled wall, viewed from the inner or furnace side;

Fig. 2 is a view similar to Fig. 1 but showing,

the wall before the application of refractory material thereto;

Fig. 3 is a section on the line 3--3 of Fig. 1;

Fig. 4 is a device;

Fig. 5 is a side elevation of the anchoring device; and

Fig. 6 is a perspective view, on a reduced scale, of a special wrench used in assembling the wall.

The embodiment illustrated comprises a row of cylindrical metal tubes l0 axes vertical and in a common plane, a relatively narrow space being provided between anjacent tubes. These tubes may form a part of a furnace wall, and water or other fluid may be circulated through them in a well-known manner to cool the wall and to absorb radiant heat from the furnace.

On the inner or furnace side of the tubes I 0 we mount ,a series of blocks Il, preferably of a suitable heat resisting cast metal. Each block, as shown particularly in Fig. 4, is substantially triangular in plan, with two concave cylindrical surfaces l2 converging outwardly and arranged to nt in close contact with the convex surfaces of two adjacent tubes I0. From the outer side of each block H there projects a fastening deperspective view of an anchoring vice in the form of a comparatively thin rectan-l gular metal plate Il located in a vertical plane and arranged to extend between the tubes I0 and for a substantial distance outwardly of the tubes. This plate Il is suitably secured to the block midway between the concave surfaces l2,

together.

The plate H is made of a suitable malleable material, such as steel, adapted to be deformed by the application loi' sufficient force thereto. This property of the plate is utilized when the blocks are assembled on the tubes, the plates being inserted between the tubes. whereupon the outer end portions of the plates are twisted through an angle of approximately ninety degrees into a substantially horizontal plane, as shown in Fig. 3. As a result of this twisting of the plates. the blocks il are drawn into very rm contact with the tubes. To facilitate the twisting of the plates, we employ a special wrench shown in Fig. 6 and comprising an elongated` heavy metal .bar i1 having a slot iil through the central portion thereof ofthe proper size to fit over the plates. The end portions I9 of the bar are bent outwardly at a slight angle to avoid interference with the plates of blocks already in place on the tubes.

In some installations the blocks `ll may be placed closely together and they may -by themselves afford suflicient protection to the tubes I0. However, in many cases it is desirable to install refractory material on the inner side of the tubes to reduce the transmission of heat to the tubes, thereby increasing the temperature in the furnace and facilitating the ignition of the fuel. When refractory material is to be used, the blocks Il in each vertical row are spaced apart and the blocks in adjacent rows are staggered, as shown particularly in Fig. 2. In addition, projecting lugs 2| are formed on the inner faces of the blocks, these lugs being T-shapedas best shown in Fig. 4. After the blocks have been mounted on the tubes,A refractory material 23 is applied in plastic form over the inner side vof the tubes and blocks. The T-shaped lugs 2l will be so interlocked with the refractory material as to retain the latter firmly in place.

a comparatively simple and effective construction for a furnace wall of the fluid cooled type, this wall including parallel metal tu s which can extent. The tubes can be closely spaced, since the metal plates I4 are relatively thin. No welding of parts to the tubes is required.

Hav-lng thusdescribed our invention, what we claim as new and desire to secure by LettersPatent is:

1, A furnace wall comprising a row of parallel cylindrical metal tubes with narrow spaces between them, blocks mounted on the inner side of the tubes and each having two concave cylindrical surfaces in contact with the surfaces of two adjacent tubes, and relatively thin plates of malleable metal extending outwardly from the the plates being so twisted as to engage the outer surfaces ofthe tubes and to pull the blocks outwardly into firm contact with the tubes. l

2. A furnace wall comprising a row of parallel metal tubes with relatively narrow spaces between them, blocks engaging'the inner sides of the tubes, and comparatively thin plates of malleable metal extending outwardly from the blocks between the tubes, the inner portions of the plates adi acent the blocks being parallel with the axes of the tubes, and the outer portions of the plates being twisted into planestransverse to said axes to engage the outer surfaces of the tubes and to pull the blocks outwardlyuinto flrmcontactwith the tubes. .j` -j ,l v

3. A furnace wall comprising a. lrow of parallel metal tubes with relatively narrow spaces between It will be apparent that the invention providesbe shielded from the radiant heat to anyv desired l blocks between the tubes, the outer portions of them, blocks each having two concave cylindrical surfaces which converge in the outward direction and engage the inner sides of the tubes, and comparativelythin plates of malleable metal extending outwardly from vthe blocks between the tubes, the inner portions of the plates being located between the said converging surfacesand the outer portions of the plates being twisted into planes transverse to the axes of the tubes to engage the outer surfaces of the tubes and to pull the blocks outwardly into rm contact with the tubes. f

4. A furnace wall elementcomprising a block having two concave cylindrical surfaces on opposite sides thereof and convergingr in theoutward direction, the axes of said `surfacesy being,v parallel, and a comparatively thin platepf r'nal-` leable metal secured to the outer portion Vof lthe block. the plate lbeing located midway,between'` said axes and parallel thereto, theplatepextending at right angles with the plane of said axes and being adapted to be twisted to secure the block against the tubesof av furnace wall.

5. A furnace wall element comprising a comparatively thin plate of malleable metal and a metal block` cast about the inner portion thereof and interlocked therewith, the block having two concave cylindrical surfaces located atiopposite sides of the plate and converging in the outward direction, the 'outer portion ofthe plate being adapted to be twistedto securetheblock against the tubes of a furnace wall.

MAXH. KUHNER. l GUsTAv aREHM; 

